Background: Virtual reality (VR) programs based on motion capture camera are the most convenient and cost-effective approaches for remote rehabilitation. Assessment of physical function is critical for providing optimal VR rehabilitation training; however, direct muscle strength measurement using camera-based kinematic data is impracticable. Therefore, it is necessary to develop a method to indirectly estimate the muscle strength of users from the value obtained using a motion capture camera. Objects: The purpose of this study was to determine whether the pedaling speed converted using the VR engine from the captured foot position data in the VR environment can be used as an indirect way to evaluate knee muscle strength, and to investigate the validity and reliability of a camera-based VR program. Methods: Thirty healthy adults were included in this study. Each subject performed a 15-second maximum pedaling test in the VR and built-in speedometer modes. In the VR speedometer mode, a motion capture camera was used to detect the position of the ankle joints and automatically calculate the pedaling speed. An isokinetic dynamometer was used to assess the isometric and isokinetic peak torques of knee flexion and extension. Results: The pedaling speeds in VR and built-in speedometer modes revealed a significantly high positive correlation (r = 0.922). In addition, the intra-rater reliability of the pedaling speed in the VR speedometer mode was good (ICC [intraclass correlation coefficient] = 0.685). The results of the Pearson correlation analysis revealed a significant moderate positive correlation between the pedaling speed of the VR speedometer and the peak torque of knee isokinetic flexion (r = 0.639) and extension (r = 0.598). Conclusion: This study suggests the potential benefits of measuring the maximum pedaling speed using 3D depth camera in a VR environment as an indirect assessment of muscle strength. However, technological improvements must be followed to obtain more accurate estimation of muscle strength from the VR cycling test.

본 연구의 목적은 디지털 트랜스포메이션의 도입이 가속화 된 경영 환경 속에서 조직 내 인적자원개발(human resource development: HRD) 담당자들이 경험하는 업무 변화에 대해 알아보고, 그에 따른 필요역량 및 업무 수행 시 겪는 어려움을 탐색하는데 있다. 이러한 목적을 달성하기 위해 HRD 업무를 담당하는 현직 종사자 10명을 대상으로 하여 일대일 심층 인터뷰를 실시하였다. 그 결과 디지털 트랜스포메이션시대에 HRD 담당자의 업무는 NCS 기반의 능력단위를 기준으로 하여 전통적인 업무와 비교했을 때 강화, 감소 또는 새롭게 추가된 업무가 있는 것으로 나타났다. 또한 필요 역량은 지식, 기술, 태도, 능력이라는 범주로 나누어 도출하였는데, 테크놀로지 활용 기술 및 변화에 적극적이고 긍정적으로 대응하려는 태도 및 능력이 중요한 것으로 나타났다. 전체적으로 디지털 트렌드 및 스킬에 대한 지속적인 학습으로 인해 업무량은 증가한 것으로 나타났다. 이상의 결과를 바탕으로 본 연구에서는 조직원들의 변화를 이끌어가야 하는 HRD 담당자들에게 실천적 시사점을 제시하고, 연구의 제한점 및 향후 연구 방향에 대하여 제언하였다.

본 연구의 목적은 조업기인 어업쓰레기 발생(추정)량에 대한 어업 및 해양환경 정책의 범주별 차이를 비교하고, 독립변수와 종 속변수의 상관성을 분석하는 것이다. 독립변수는 세 가지로 구분되는데, 사전 예방정책, 현행 관리정책, 사후 대응정책이다. 사전 예방정 책에는 친환경어업 지원사업, 제도적 예방활동, 물리적 차단 시설 설치가 있다. 현행 관리정책에는 관련 선박 운영, 어업질서 확립, 어업 구조조정, 어장환경 개선이 해당된다. 사후 대응정책에는 하천~해안변 쓰레기 정화, 해양·침적·부유쓰레기 수거, 조업 중 인양쓰레기 수 매, 어업관련 폐기물 처리, 해양쓰레기 피해복구가 포함된다. 측정지표는 각 사업별 결산액이다. 종속변수는 조업으로 인한 어업쓰레기 발생 추정량이고, 측정지표는 연안 통발 및 자망과 그 부속어구 유실량의 합이다. 평균순위 차이 검증결과 어업쓰레기 발생 추정량은 해 역별로는 동해안이 가장 높게 나타났고, 기초자치단체별로는 시 지역이 가장 높게 나타났다. 해양환경 관련 결산액은 군 지역에서 가장 많이 투입하고 있었고, 대부분의 변수에서 유의한 차이가 나타났다. 어업쓰레기 발생 추정량과 관련있는 변수는 사후 정책 중 조업 중 인 양쓰레기 수매 사업과 폐기물 처리 지원 사업이었다.

본 연구에서는 ‘설향’ 딸기를 두 작기(2020－2021년, 2021 －2022년)에 걸쳐 재배하면서 외부 광환경과 생육도일온도 가 작물 생산량에 미치는 영향을 분석하였다. 2년 동안 온실 내 환경 관리, 양액 관리 등은 동일하게 하였다. 재배기간 중 주 간의 온실 온습도는 두 작기에서 유사하게 관리되었고, 야간 의 온습도는 통계적으로 차이가 있었으나 작물 생육 범위를 벗어나지 않았다. 일사량은 9월과 10월에 첫 번째 작기의 일 평균 일사량이 많아 누적일사량도 많았으며, 11월부터는 2월 까지는 두 번째 작기의 일사량, 3월에는 다시 첫 번째 작기의 일사량이 많은 것으로 나타나 1월부터의 누적일사량은 두 번 째 작기에서 많은 것으로 나타났다. 딸기의 최적 일장 조건인 8시간 이상의 일장이 나타난 일은 두 작기 간 큰 차이가 없었고, 변화 양상은 누적일사량의 변화와 유사하게 나타났다. 누 적일사량과 생육도일온도는 상관관계가 커 생육도일온도가 딸기의 생산량과 당도에 미치는 영향을 조사해 본 결과의 초 기의 누적일사량과 생육도일온도가 적었던 두 번째 작기에서 초기 수확량은 적었으나 누적일사량 및 생육도일온도가 증가 함에 따라 후기에 수확량이 첫 번째 작기보다 많았으며 잠재 적 최대 생산량도 큰 것으로 나타났다. 당도는 생육도일온도 가 증가함에 따라 감소하였으며, 이는 촉성딸기의 특성으로 판단된다. 추후 연구를 통해 단순 수확량뿐만 아니라 작물 생 육, 꽃눈분화 및 출뢰시기를 조사, 분석하여 생육도일온도가 작 물 생육에 미치는 영향을 다각도로 분석하는 연구도 필요하다 고 판단된다.

Corrosion products generated from the oxidation of structure materials are deposited on the surface of coolant systems, forming CRUD (Corrosion Related Unidentified Deposits). The CRUD deposition on the fuel surface has influenced the heat transfer through the fuel rod. When CRUD was deposited on a fuel surface, heat resistance may increase, and this increase in heat resistance leads to the increase in temperature distribution from cladding to coolant. Also, the temperature distribution is related to the radiolytic and chemical reactions within the CRUD deposits. This influence may be enough to change the pH distribution within the CRUD deposits. To estimate the influence of thermal resistance, the composition, microstructure, and vapor fraction within the CRUD should be considered, by investigating the thermal conductivity model of CRUD deposits. Therefore, in this study, the CRUD thermal conductivity was studied through the literature study, by considering composition, capillary flow characteristics, and vapor fraction. For the uncertainty parameters, a sensitivity study was conducted to check the degree of influence on thermal conductivity. The effective thermal conductivity was applied to the radiochemistry model within the CRUD deposits and an analysis of the influence in radiolysis reaction within the CRUD deposits with a fixed thickness.

The decommissioning process of Kori Nuclear Power Plant No.1, which was permanently suspended in 2017, various studies and attention on the decommissioning of nuclear power plants and waste management are being focused. In particular, decommissioning of high-risk facilities should take into account both safety and economic aspects. Small defects in the decommissioning process may lead to major disasters, and the resulting economic losses will cause enormous damage at the national level. In order to prevent such damage, various decommissioning process simulations within a virtual environment should be performed, and process errors and results should be collected and analyzed through simulation to derive the optimal decommissioning scenario as possible. The platform introduced in this paper builds a virtual environment based on drawing and modeling data of Kori Nuclear Power Plant No.1 and automatically creates an optimized cutting path for dismantling the facility and internal structure, and simulates a cutting process similar to reality using Robot Arm. In addition, it is possible to derive and analyze a cutting process scenario by processing process results such as time required for work and cutting distance collected through simulation.

Concrete is used as the main engineering barrier in low and intermediate level radioactive waste disposal facilities. As the time passed, the radionuclides stored in repository may contact with groundwater and leak into the ecosystem through the rock media. In this process, the radionuclides can react with calcite via sorption or coprecipitation, because calcite is the major mineral of concrete. Under the various background conditions in repository, frequent dissolution-precipitation reactions can happen. Dissolution of Sr-coprecipitated calcite may be different from that of SrCO3(s) which can mislead the safety performance of radioactive Sr and the estimate of Sr mobility based on the solubility of SrCO3(s). Strontium is not only one of the fission products but also emits beta rays with a long half-life almost 29 years. The strontium may be released or retarded by the dissolution-precipitation reactions in repository. In this study, the dissolution of Sr-coprecipitated with respect to calcite was tested in various environment conditions. The Sr-coprecipitated calcite, (Sr,Ca)CO3(s) was synthesized by coprecipitation method in alkaline condition. The 250 mL of 0.1 M of CaCl2 solution was mixed with 250 mL of 1.14 mM SrCl2·6H2O solution. Then, independently prepared 500 mL of 0.1 M Na2CO3 solution was mixed with the mixed solution of CaCl2 and SrCl2. The precipitates could be made and they were aged for 3 days at room temperature. Then, the supernatant was separated by the centrifugation and the solid at the bottom was dried in an oven at temperature 80°C. After that, the Srcoprecipitated calcite powder was washed using the DI water several times and dried again before use. Characterization of solid powder was conducted by XRD and SEM, and the ICP-MS and ICP-AES were used to analyze the concentrations of Ca and Sr. The batch dissolution experiment was conducted with a solid-to-solution ratio of 10 g/L groundwater in polyethylene tubes. The oxidative groundwater was synthesized by simulating the chemical composition of KAERI Underground Research Tunnel (KURT) DB-3 groundwater. Different temperatures and pHs were prepared and tested for the release of Sr and Ca from the coprecipitated (Sr,Ca)CO3(s) to compare the results with the release of Sr and Ca from SrCO3(s) and CaCO3(s), respectively. Such as, these results will be used to provide better understanding of Sr release and mobility in various repository environments.

Glass wool, the primary material of insulation, is composed of glass fibers and is used to insulate the temperature of steam generators and pipes in nuclear power plants. Glass fiber is widely adopted as a substitute for asbestos classified as a carcinogen. The insulations used in nuclear power plants are classified as radioactive waste and most of the insulation is Very Low-Level Waste (VLLW). It is packaged in a 200 L drum the same as a Dry Active Waste (DAW). In the case of the insulations, it is packaged in a vinyl bag and then charged into the drum for securing additional safety because of the fine particle size of the fiberglass. A safety assessment of the disposal facility should be considered to dispose of radioactive waste. As a result of analyzing overseas Waste Acceptance Criteria (WAC), there is no case that has a separate limitation for glass fiber. Also, in order to confirm that glass fibers can be treated in the same manner as DAW, research related to the diffusion of glass fibers into the environment was conducted in this paper. It was confirmed that the glass fiber was precipitated due to the low flow velocity of groundwater in the Gyeongju radioactive waste repository and did not spread to the surrounding environment due to the effect of the engineering barrier. Therefore, the glass fiber has no special issue and can be treated in the same way as a DAW. In addition, it can be disposed of in the disposal facility by securing sufficient radiological safety as VLLW.

In biosphere assessment modeling for the safety assessment of the Wolsong LILW disposal facility, the multi-compartment modeling in which all radionuclides transport is described quantitatively in terms of transfer factors between various environmental compartments has been implemented. In order to reflect the actual transfer mechanisms of 14C in the environment the specific activity (SA) modeling approach can be applied as an alternative to the previous transfer factors (TF) approach. The assumption of full SA equilibrium throughout the terrestrial environment is completely satisfactory for 14C release to the atmosphere if the 12C is emitted as 14CO2. This is the only form that is readily taken up by plants, so that active carbon is incorporated into the plant via photosynthesis at the same rate as stable carbon. Accordingly, the 14C concentration in Bq/g stable carbon is the same in the plant as it is in the air. And animals take up carbon almost entirely through ingestion and the SA ratio in the plant is maintained in the animal. In this study, a specific activity model for 14C was implemented in a GoldSim biosphere assessment model. From the literature survey for existing specific activity models developed, the IAEA model was selected. The farming scenario utilizing well water was simulated and the resulting ingestion dose conversion factors (DCFs) from the IAEA SA model were compared with those of the TF approach. The parameter value for the concentration of stable carbon in the air (gC/m3) is used as 0.20 gC/m3 considering the Suess effect. The dose coefficient for food ingestion used for dose calculations was taken from ICRP-72 as 5.8E-10 Sv/Bq. It was found that the ingestion DCFs of the SA model showed about 3 times lower than those of the TF model in the farming scenario through irrigation of well water, so it is expected that the SA approach could be applied for a more realistic assessment. Though the comparisons were made on the results from the terrestrial ecosystem only in this study, it would be necessary to investigate the applicability of the SA modeling approach for 14C through extensive comparisons and analysis including an aquatic ecosystem, and through parameters survey suitable to the domestic condition.

In Korea, borated stainless steel (BSS) is used as spent fuel pool (SFP) storage rack to maintain nuclear criticality of spent fuels. As number of nuclear power plants and corresponding number of spent fuels increased, density in SFP storage rack also increased. In this regard, maintain subcriticality of spent nuclear fuels was raised as an issue and BSS was selected as structural material and neutron absorber for high density storage rack. Because it is difficult to replace storage rack, corrosion resistance and neutron absorbency are required for long period. BSS is based on stainless steel 304 and it is specified in the ASTM A887-89 standard depending on the boron concentration from 304B (0.20-0.29% B) to 304B7 (1.75-2.25% B). Due to low solubility of boron in austenitic stainless steel, metallic borides such as (Fe, Cr)2B are formed as secondary phase metallic borides could make Cr depletion near it which could decrease the corrosion resistance of material. In this paper, long-term corrosion behavior of BSS and its oxide microstructures are investigated through accelerated corrosion experiment in simulated SFP condition. Because corrosion rate of austenitic stainless steel is known to be dependent on the Arrhenius equation, a function of temperature, corrosion experiment is conducted by increasing the experimental temperature. Detail microstructural analysis was conducted with scanning electron microscope, transmission electron microscope and energy dispersive spectrometer. After oxidation, hematite structure oxide film is formed and pitting corrosions occur on the surface of specimens. Most of pitting corrosions are found at the substrate surface because corrosion resistance of substrate, which has low Cr content, is relatively low. Also, oxidation reaction of B in the secondary phase has the lowest Gibbs free energy compared to other elements. Furthermore, oxidation of Cr has low Gibbs free energy which means that oxidation of B and Cr could be faster than other elements. Thus, the long-term corrosion might affect to boron content and the neutron absorption ability of the material.